The sea, it calls me
by MochiUs
Summary: One was searching for what was lost. One was looking for what was rightfully his. They were creatures of the sea, and this was their tale. This was the story of how a selkie and a merman fell in love.
1. Chapter 1

The sea is his home, and it calls him. The sea was where it all began, and the sea is where it will all end.

Izuku Midoriya was free, just like he should be. He was held captive for so long, but now he could return to where he belonged.

Then he took a deep breath and breathed in the salty air from the ocean. He curled his feet into the ground and dug them deep, wiggling his toes until grains of sand got stuck underneath his nails. The ocean breeze brushed against his hair, combing its tangled mess back as if it prepared him for his return. He gripped his coat tighter, but he was not afraid nor apprehensive. He was ready. He was more than ready.

Then he closed his eyes and dove for the waters, for he was one with the sea once more. This was his story. This was his tale. This is how he fell in love with the sea and how the sea fell in love with him.

* * *

Bakugou Katuski was in a mood. It was an exhausting cycle. He willed the waters, controlling them with his emotions. He pushed the waves, translating his anger into the currents. He called for the ocean to enact his revenge.

Humans were the bane of his existence, and though he crossed paths with some good ones, most of them were rotten. Dirty. Despicable. He hated humans with every fiber of his being, for they didn't deserve forgiveness. They didn't deserve the ocean and the wonders it provided. They take and steal and abuse. There were efforts. He knew they tried. They tried to change, to clean the ocean, to reverse the damage they had wrought, but they barely pulled through. All Katsuki witnessed was destruction, and if the humans were so desperate for it, then he might as well give them an early present.

He was on his merry way to do exactly that, wreaking havoc and sinking ships, until a seal collided into his merman frame and caught him surprise. Katsuki sputtered, caught off-guard by this anomaly and redirected his hand in the mammal's direction. With one flick of the wrist, this stupid seal could end up as lubber and lard.

"Move," he snarled.

Most sea creatures understood his superiority, his status as the protector and leader of these waters. Most sea creatures would swim away in fear of provoking this predator, but this seal was different. This seal refused to back off.

Instead, it swam closer, pleading him silently with those big, doe eyes. It was a pacific harbor seal, Katsuki thought from the top of his head. A short guesstimate told him that it was almost his length.

"Shoo," he flapped his hand away at the seal. "Leave me alone. Go and eat some fish."

Instead of swimming away, the seal went the opposite direction and charged after Katsuki, who was struck by its odd behavior. Though they had the capability to be aggressive, Katsuki was not invading its territory nor was it mating season.

Katsuki said, "What the fu-"

The seal slammed into his abdomen, leaving him off-kilter. His tail swished around, trying to regain his balance, but the seal was having none of that and went on the offense again.

"That's it!" he growled and slapped his tail against the creature's cheek.

He refused to be one-upped by a stupid seal and knocked into its fat body. The seal made grunting noises as he wrestled with it, wrapped around its girth, and slammed it into the sea bed. It wriggled around under his hold, but Katsuki was a merman, one of the strongest of his kind. A mere seal cannot overpower him.

"Hah," he smiled victoriously. "I win."

He transferred all his weight into the seal, and it struggled to be free but couldn't. It was at his mercy. He heard it whine, but it held a flame, a type of determination not commonly found in his opponents.

"Usually I would kill such a foolish creature," he said haughtily and tightened his grip.

For a second, he swore the seal snorted and rolled its beady eyes.

"But I'll spare you since you entertained me," he said and released his hold.

He half-expected it to run with its tail tucked between its nonexistent legs, but after these past few moments, he should have known better as the seal stood its ground. Katsuki ignored its challenging expression and raised his eyes to the surface where the storms still raged on. He tried to tap back into that relentless rage, to rile himself up to continue the chaos above, but the swirling emotions he felt dissipated.

He felt empty, and it was all thanks to this seal who set him off-balance.

"I guess you got what you wanted," he said, straight-faced.

He felt calmer; he despised it.

He rose his hand and clenched it, ending the torment of the surface world. Tonight, the merman was done with his emotional plight. He was about to sarcastically congratulate the seal for achieving his goal and ask if it was happy with snark as a side dish, but when he turned around, the creature disappeared.

"Huh." There was only the sea. "Weird."

He whirled around to double-check its whereabouts, but the seal was nowhere to be found. It was as if it vanished, but no normal seal could disappear out of thin air. Katsuki would have detected its presence by now, but he got nothing. Nada. Zilch. He floated there, waiting for any sign of movement, but hypothetically if the seal escaped, it would have been long gone by now. With a wary glance back at the deep, blue sea, he swam away and returned to his underwater cave where he could once again isolate himself from the humans, from sea life, from the hole in his heart.

Lest did he know, he would meet the seal again. Very soon. And in a different form.

* * *

Today Katsuki craved for human flesh, to devour and feast on their meaty carcasses and pick his teeth with their bones. His appetite was insatiable. May mercy rest on the soul of his next victim as he scoured the coastline of the island he circled around, lurking beneath murky waters.

It was early morning, the dawning sun barely peeking out from the horizon. Less people loitered around the sandy beaches, but every now and then, he managed to lure in a hapless bystander.

Katsuki's target was in full view. Katsuki leered at the green-haired man traipsing at the edge of beach, and for a minute, he observed his prey's movement with annoyance. The human hovered between water and land with unsteady steps like a newborn, and Katsuki, if he wasn't so concentrated on eating him, would have splashed a tidal wave against his feeble body.

Katsuki was hiding behind a large rock. His fingers grappled it tighter as the man approached closer and closer. He licked his lips as his eyes graciously trailed over the human's form. He admitted that this man looked better than the other ones he consumed in the past. The human wore an unzipped mint sweater and a pair of swimming trunks, leaving his chest out in display. Katsuki salivated at the thought of plunging his fangs into the meatier parts of the human's chest and abdomen. He delighted in the drained look of their faces, pleading for mercy in their expression. The magic of being ravished by a mermaid was a fluke, a disillusioned lie, and Katsuki was happy to oblige.

Katsuki's grip and insane strength left indents into the stone as he ogled the man, who waddled into the water with a bright smile plastered on his face. The sunlight highlighted his beautiful green locks and the freckles that peppered all over his toned body. The man's sun-kissed skin made him look more delectable, desirable, and Katsuki couldn't wait to get his hands on him. This human was worth more than a measly morsel; he was fresh gourmet. His tail flicked in glee as Katsuki anticipated the moment he could wrap his hands around that lithe body and drown it to the bottom of the ocean, watching him squirm until his last breath. Though he survived off fish and other sea creatures, the taste of a human could never compare.

It has been months since he had a good meal, and though he was surviving through fish and other sea creatures, the taste of a human was fresh in his mind. He sidled closer, confident that his ethereal features would captivate the unsuspecting human. After all, his crimson tail garnered attention and praise from the seven seas. Mermaids would turn green with envy every time he passed by them, his dorsal fin decorated with streaks of red and gold. The fin fanned out, much like a betta, and the lower portion of his tail was speckled with silver scales intermixed with the vibrant, iridescent red ones. Overall, he was a looker, but if all else failed, he could just use his last resort and sing a lullaby to entrance the human, drift him closer and closer until his grabby hands could fully embrace him and plunge him to his untimely death.

He had dawdled long enough. Ready to have his breakfast, Katsuki contracted his muscles, splashed his tail against the water, and made his presence known. The green-haired man whipped around at the disturbance. He sucked in a sharp breath, eyes widening at the sight of his magnificent existence, an existence that shouldn't be remotely possible, but it was.

"Wow," he let out an awed breath.

The man released a blinding smile, one that was so radiant that it was more likely to give Katsuki sunburn than the sun's rays beating down his back. A normal human would have fallen to his feet, kissing the very sand Katsuki touched. Yet, this human approached without a care in the world, sloshing the waters as he practically skipped into the ocean.

"Are you going to eat me?" he asked excitedly, brimming with curiosity.

Taken aback, the merman pulled up his defenses. He was wary by the man's reaction. Well, worst case scenario would be the guy ending up as a psychotic scientist who traveled the ends of the earth to hold him in captivity and dissect him for his unethical experiments. Katsuki hoped that he didn't attract that type of man. He heard rumors and horror stories from mermaids who experienced that type of shit.

"Please!" the man shouted as Katsuki made a break for it. "Don't run!"

Obviously, Katsuki wouldn't run. He doesn't have legs.

However, he doesn't see the harm in the human getting closer. Despite the red flags, Katsuki chose to stay and floated in place. After all, he was not a damsel in distress. He knew how to fight.

The man was soaking wet from head to toe. Water covered most of his body until only his head was bobbing at the surface. With strict scrutiny, Katsuki hesitantly swam closer until he had a good frontal view of the man's face. He was a gorgeous specimen up close.

It looks like constellations were splayed across his rosy cheeks. There were faint dimples at the corners of his mouth. Katsuki was a goner, getting lost in those dazzling, emerald orbs.

His sense of direction was impeccable. Even the mightiest of tsunamis could not leave him astray, but here he was, beguiled by a pretty set of eyes. Merfolk were weak to precious gems and jewels. With that last thought, the realization clicked.

"You," he gasped and pointed at him with a growl.

This man was no human.

Katsuki sounded scandalized. "You're that seal from earlier."

"To be more precise," said the seal, "I'm a selkie."

"You little shit." Well, this ruined his appetite. He was not a fan of eating seal. "What the hell is a selkie doing here in Japan? Isn't your species supposed to," Katsuki waved his hand, "Hang out in Scotland or whatever?"

The seal simply grinned a crooked smile, showed off his dimples, and said, "We selkies can _hang_ wherever we please."

His hand reached out to pet his matted, golden hair. The seal was bold, bolder than any creature Katsuki had ever laid his eyes on. The merman twitched as the seal's fingers brushed against the fins on his ears, but steadily relaxed as they then carded through his bangs.

"So," the seal said quite humorously, "The rumors were wrong. Mermen aren't as hideous as they seem."

Then he jumped when Katsuki bumped his tail against his legs.

"Who the hell said that?" Katsuki said with a raised eyebrow. He glowered. "I'll kill them."

"It's all in the lore," replied the seal, shaking his head. "So I just assumed mermen were inherently ugly since I never saw one."

"What shit reasoning is that?"

"Not my fault you guys rarely pop up," he shrugged.

His nimble fingers traced around his sinewy biceps with interest, and Katsuki may or may not have flexed them as the seal explored his body.

"The elders never warned us how devastatingly beautiful you would be," he told Katsuki, awestruck and breathy.

The seal smiled so much, the merman thought it was permanently etched into his face.

"I'm very flattered that a merman of your caliber chose me as potential prey," he said and let out a light laugh.

Without warning, Katsuki's tail coiled around his leg. The man yelped and shivered from the sensation of the scales skittering across his skin. They tickled.

"Stop that!" the man told him hotly and batted his chest with his fists.

"Or what?" Katsuki challenged. "Your coat is yards away from here," he said cockily. "And you're trapped in my clutches."

The seal attempted to wriggle himself out to test his chances, but his legs were locked tight. He was barred from escape. It was one of the disadvantages of being in this form.

Dejected, the seal grunted out his disapproval and raised his hands up in surrender.

"There, happy now?" he pouted.

Katsuki rolled back his shoulders and lolled back, enjoying the view. Merfolk were famous for being capricious and fickle, so being true to his species, Katsuki let go of his initial anger of being called ugly. He toyed with his new friend instead.

"Yes," he purred, "I am."

"Then…" the seal paused. "Can you put me back on land?"

The merman drifted closer to the shore but still wore a pondering look. "Maybe," he said vaguely. "I will if you tell me."

"Tell you what?"

"Tell me what you're doing here."

When Katsuki mentioned about the purpose of his stay on dry land, the man tensed up and immediately clamped his mouth shut. He was holding secrets. The easygoing attitude he wore was stripped away.

Katsuki continued nonetheless, "Sure, you selkies can travel and mingle with humans. The world is our oyster, but…"

Even though he said that selkies could interact with humans, his personal stance on how much communication was deemed appropriate between the creatures of the sea and humans was stifling. To each his own.

"But why here?"

He knew about the tragedies of selkies. They were often manipulated and taken advantage of. He had to ensure that he was not returning the selkie to some treacherous wretch who stole his coat. The seal bit his bottom lip and casted his eyes downward. Katsuki waited for the affirmation to his fears, but the man still said nothing.

With the silence between them, Katsuki took this opportunity to listen to the sounds of the beach, to the music of his home. The distant foghorns from the ships. The squawking seagulls overhead. The crashing waves against the rocks. Katsuki supposed this was one of the few uplifts of the surface world. The noise underwater had its own charm, but the noise above was more diverse and lively. Some days only the sounds of nature filled the air, but on some nights, there were fireworks, explosions of light and colors painting the night sky. He never told a single soul, but on those nights, they were his favorite. They reminded him of the past. They reminded him of what he had until he lost it in the blink of an eye.

The seal finally recomposed himself in time.

"Once upon a time," he said with a singsong voice.

His eyes twinkled like stardust. He gazed the merman with firm and gentle resilience.

"I lost something valuable here… a long time ago," he explained. "Actually…" he chuckled sadly. "I guess to us it wasn't that long ago, but to him…" he paused, "It was."

Like mermaids, selkies aged slow, and they had long-lasting lives. Selkies rarely died unless their coat was compromised, or the selkies themselves were killed by a predator during their transformed state. Whether he referred to ten years or decades, he looked older when he said that, reminiscing his mistakes from the past. Katsuki felt a tug in his chest because he, too, made mistakes in his youth.

"And what about you?" the seal redirected his attention.

"What are you talking about?" Katsuki groused.

The seal's gaze itched him, as if they could peer into his heart.

"Aren't you looking for something, too?"

It stung to hear that question, as if he was still a small, naïve fry who bravely touched a jellyfish's tentacles. The pain was insufferable, but he toughed it out and withheld the well of emotions rising in his throat. The pain would pass, he told himself. There was no need to dwell into that can of worms.

"What makes you say that?"

"Well," the seal said thoughtfully, brushing his hands against the merman's brilliant crimson tail. "It's because you looked like a fish out of water back there," he referenced their first encounter, the night where Katsuki went out of control.

Unamused, Katsuki released his hold and dropped the seal like a bomb. He hoped he would drown for making such a tasteless joke. The man sputtered around as water rushed into his mouth. His hands were splayed everywhere as he tried to regain his balance and float.

Katsuki wrinkled his nose and clicked his tongue. "You're weird."

Once he righted himself, the seal latched onto his arms and laughed loud and hard. It was an ugly sound, full or snorts and wheezes and guffaws. One would even debate that his laugh sounded similarly to a seal's. In the end, Katsuki stuck up his middle finger and gave him the bird, one of the few customs he accepted and copied from the humans. The seal took no offense to that and swam back to the shore. He waved his new friend farewell, promising that they would meet again. Katsuki scoffed and descended back into the dark depths of the ocean.

* * *

"Word on the shore says that you're fucking a seal."

If Katsuki was a normal human with two legs, he would have done the equivalent of choking on his coffee and spewing it out of his mouth. However, he was not, so he choked on his half-eaten tuna and spat it out. His pink-haired friend shrieked in disgust and backed away. Extending her hands, acid was dispersed from her fingertips, melting those bits away in a flash.

"Gross," she said and showed her repulsion with her tongue sticking out of her mouth.

Katsuki was still sputtering from the atrocities he heard. He wiped away his excess spit from the back of his hand.

"What?!" he yelled.

Mina gasped and covered her mouth. "Is it true? Are you really fucking a seal?"

"No!" he hissed. "Stop saying it like that!"

Mina's ears must have been plugged because her thoughts kept running rampant over the distressing news.

"I thought they were joking," she groaned and ruffled her hair until it puffed like a puffball. She was trying to accept Katsuki's taste in partners. "I guess it's possible," she clenched her eyes and tried not to gag as she added, "Since seals typically mate in the water so-"

Katsuki curtailed her train of thought quick by karate chopping her head, a chop that would eventually leave a swelling bump. Mina shielded herself right away.

"Hey!" she pouted. "What gives?!"

"That's for saying stupid shit," Katsuki growled. "I'm not fucking a stupid seal, and I never will," he crossed his arms, daring Mina to continue with her ridiculous fantasies. He was in a sour mood, and it was all thanks to that infuriating selkie. "Where did you even get that idea?"

Tapping her chin, Mina said, "Well, first, I heard it from Uraraka, who heard it from her cousin, who heard it from her sister's mate, who eavesdropped on a conversation between Kendo and Yaoyorozu about how their friend accidentally stumbled upon you getting down and dirty on a-"

"That's enough," Katsuki's voice boomed.

Even though Mina owned the heart of a saint and could deal with Katsuki, the feeling was not entirely mutual from Katsuki's end. She was overly perky and outgoing. She knew how to dig deep into his skin, to reach into his last nerve. Though he blamed half of his annoyance with the rest of his brethren to mermaid culture since they were expected to be vain and obsessed with the next shiny object, he blamed the other half with himself. It was difficult to connect with the mermaids, especially flighty ones who gossiped like crazy.

From the get-go, Mina was in a different category from those extras. Her appearance was already unique by itself. Her skin held a pinkish tinge, and it shimmered like diamonds, sparkling as if they were right under the sun. Her tail had an ombre effect that went from a cute teal to a darker violet hue. Her slim elongated tail held distinct indigo markings, but instead of shying away from their weird designs, she wore them with pride and confidence. Her athletic prowess was easy to see whenever she zipped by her other peers, but her hair would always look as soft as a feather. Besides her beauty, her gifts were invaluable. She had the ability to secrete poison, a poison that was nontoxic until she chooses to make it so. Suitors would swarm to her cave to propose and mate with her irresistible self, but like Katsuki, she was not completely satisfied with the common life. The two of them had their sights on bigger, otherworldly treasures.

To a mermaid, their greatest treasure was their livelihood.

For example, Uraraka's greatest treasure was her speed. Mermaids praised her for her weightlessness, so without that gift, a large chunk of her identity would be absent.

Once upon a time Katsuki had his treasure, but alas, he was a fool to lose it.

* * *

Katsuki's next encounter with the selkie happened two weeks later. Mind you, this was unexpected, and Katsuki was not, by any means, stalking him. This was uncalled for. The selkie himself had no right to look that good in plain drawstring shorts and wet, splayed hair. He looked like a goddamn treat with his washboard abs and 1000-watt smile. Too bad seals were not a part of his diet, which was fine. He found alternatives.

This one alternative, also known as his next victim, was some lame ass loser who cheated on his girlfriend. He would know. He eavesdropped the whole conversation as he made out with some random bland-looking woman on a surfboard. Katsuki couldn't help but question humans and their tastes. This guy was average at best. Although the guy was not as aesthetically pleasing as the seal, he was meaty enough to compensate for the looks. Hey, at least he fitted the bill.

With his cravings sated, he can finally interact with the seal with his mouth rather than his stomach. However, the element of surprise was yanked away from him as the selkie stared in his direction.

"Are you following me?"

Crap. Katsuki was stuck there like a deer in headlights. He wrongly assumed that his presence was shrouded, but that was not the case as the selkie swam closer. His swimming was graceful like a butterfly, gliding through the water with ease. Even though he was in human form, he maneuvered around the water as if it was butter.

Katsuki had plenty of time to dive underwater and take refuge in his cave, but he was held captive by his bewitching movements and was left to stare until a moss-colored head popped out. Droplets splashed onto Katsuki's cheek as the selkie shook his head and wiped the salty remains of the ocean from his face.

"Hi," the selkie said breathlessly. "Funny how we keep meeting each other, huh?"

Once Katsuki find out the secrets of what made the selkie so enthralling to him, it was over for the little bastard.

"No, it's not," he glared back at the seal's withering look.

The man bit the inside of his cheek and wore an amused look. Honestly, he wanted to tease this merman but thought better of it since he wanted to keep him as his company for a while longer. He chose correctly.

Inspiration struck him. He took out his hand and offered it to Katsuki.

"Midoriya Izuku," he said.

If possible, Katsuki's frown grew deeper. "Hah?"

"My name," said the man. "We've met before," he stated the obvious, "But we never introduced ourselves properly."

"Midoriya Izuku," Katsuki repeated after him.

"Yup!" His tone was godawfully cheery. "That's my name. What's yours?"

Katsuki spat at the water. "Not telling you."

Izuku gasped. "But I told you my name."

"Yeah, and I never asked for it," Katsuki argued back. "Besides," he said and wiped away an imaginary spot on his shoulder, "I don't care what you're called. You're still gonna be a stupid seal to me."

Izuku did not pout. There was not even a trace of the selkie being upset.

Instead, he tapped his chin in thought.

"Hmmm…"

Well, that proved to be an issue. After all, without a given name, the merman was nameless, which was completely unacceptable to his standards because names held power. They held meaning. They were a title that defined their existence. Since he barely had anything to work with, he had to create a nickname on the spot.

He glanced over at the merman, who was grumbling an earful about seals and selkies and the ilk. Realization crossed his expression. He snapped his fingers with a look of jubilation.

"Dandelion!"

Like a judge, Katsuki struck it down. Hard. "Rejected."

Izuku clicked his tongue and asked, "What's wrong with Dandelion?" He closed his eyes and added confidently, "I think it's a wonderful name."

"The hell is a dandelion?" Katsuki bared his teeth. "I don't know what it is, but it sounds degrading."

To be quite honest, he thought the seal spoke a foreign language until he realized that it must have been human-related. Distaste coated his tongue. He does not want to be associated with humans whatsoever.

"Well," the selkie drawled out, using two of his fingers to tiptoe and climb Katsuki's shoulder, "What should I call you then?"

The selkie was cute. Katsuki would give him that.

Before he was given the chance to say something obnoxious or horrifying like King Explosion Murder, he heard a splash from behind. In other words, a new intruder was here, and they almost scared the shit out of him.

He whipped his tail to attack. Alarm bells were ringing in his head. The seal was with him, so his defenses were cut in half, but he was willing to protect him and his own hide no matter what. He was planning on trapping the intruder into a whirlpool of some sorts, but before he was a hair's breadth from disposing the newcomer, he stopped midway.

It was Mina.

Of course, with his horrid luck, it was Mina. Thankfully, Katsuki had an immense amount of self-control, so Mina was left unscathed.

However, Katsuki was left to fight off Mina. Between a pod of killer whales and Mina, he would try his luck with the whales.

Mina, as usual, did not disappoint and freaked out.

"Oh. My. God."

The mermaid was fanning her face excitedly, squealing with delight as Katsuki stayed in the background.

Katsuki does not dare to look directly at his friend. He was already getting secondhand embarrassment from her performative excitement.

"Is that," she swam to Izuku and stole him from Katsuki's arms.

"Hey!" Katsuki growled as the selkie slipped through his fingers.

Mina's eyes glimmered with childish curiosity as her hands explored the contours of his body.

"Is this the seal you were talking about?" she purred mischievously as Izuku helplessly squirmed in her hold.

He let out a squeak as her hands roamed everywhere. She patted his hair, his neck, his chest, and his-

The merman got the selkie in a headlock and jerked him away from Mina's clutches. Said mermaid puffed her cheeks as Katsuki swam farther away, almost choking his companion in the process. Can you blame her for wanting to get familiar with the selkie?

Last time she encountered a human, which was decades ago, Katsuki went into a frenzy, overreacted, and killed the nice human right then and there. He was livid. He forbade her from meeting humans alone. Sure, they were strict restrictions. One would even argue that they were incredibly harsh, but Mina understood the risks and dangers of associating oneself with humans.

After all, a human had already screwed with Katsuki once. He doesn't want the same fate to befall on another.

Enough with humans. Right now, there was a selkie in her midst, the first one she encountered in this century. Selkies tend to stick near the shores and were a solitary species unlike mermaids. She honestly doesn't know what to make of this seal, but for certain, Katsuki was infatuated. And honestly, that was a good look that she hoped would stay on him for a very long time.

After watching the two banter back and forth for minutes, Mina, the best wingman to ever live, decided to give them personal space.

"Well, I feel like a third wheel here, so I'm going to just leave," Mina told the bickering couple.

"It was real nice to meet you, Midoriya!" she said and gave him a cute peck on his left cheek.

The selkie sputtered, unaccustomed to such acts of familiarity. Katsuki struggled to keep a straight-laced face, but he must have failed since the devilish smirk she wore said otherwise.

"Bye Katsuki!" she blew him a kiss, and with that, she flipped into the air and took a nosedive back into the water.

Then there was a pause.

The seal gave him a wobbly smile, as if he couldn't decide between grinning or laughing. Either way, he won.

"So your name's Katsuki, huh?"

A beat later, the merman screamed, "Dammit Mina!"


	2. Chapter 2

Unlike their previous encounters, this encounter was... quite different.

As Katsuki minded his business and patrolled the ocean with his usual rounds. He gathered updates on the mermaids and allowed the cycle of life to do its job. Nothing was out of the ordinary. The prey was preyed upon. The weak were eaten by the strong. The extreme shit living in the deepest, darkest parts of the twilight zone stayed in their lane. Everything was alright, but then he sniffed the distinct smell of blood.

He stiffened and wrinkled his nose. He traced back to the source of that smell and found it. To a human, it must have looked like an unwelcomed smudge. Even though Katsuki could fool people into thinking that he was a human at first glance, he was a merman, and merfolk have excellent eyesight.

Therefore, Katsuki managed to discern what, or rather, who it was. He was not a mysterious blob. He was not some unidentifiable object in the distance. No, he was more special and important than that.

A lump formed at the base of his throat once Katsuki realized who it was, and the merman made a mad dash and prayed with all his might that he wasn't too late. A shark was tailing after the selkie, who was in his seal form, as he struggled to swim away from the carnivore. Thankfully, a large chunk wasn't missing from the seal, but Katsuki could tell he was bleeding profusely. There was a deep gash on the lower end of his tail.

The shark was trying to exsanguinate him, typical of their hunting habits, waiting for the seal to bleed out until he lost consciousness from the blood loss. The water surrounding him was painted red, and it only tempted the predator even more to follow him.

Katsuki panicked when he saw the jaws of death unhinged. He propelled forward and intervened. In a matter of seconds, he smacked into its enormous body and shielded Izuku. Katsuki's chest heaved up and down, his heart racing a million beats per minute. If he was a second too late, the selkie would have died.

Of course, the shark was furious, angry that its meal was taken away right under its nose, but the shark didn't attack Katsuki. Like all sea animals, the shark knew the basic rule to never mess with him. It knew where it stood in the food chain compared to the merman.

Katsuki's eyes glowed, flashing as a warning to show who was boss. As the shark swam away, Katsuki grabbed Izuku's unmarred flipper and assisted him back to the surface. It was a rough swim, but there was a clear attempt at being gentle. However, the seal was dead weight. Katsuki practically had to haul the selkie back to shore.

Izuku was panting heavily as Katsuki dragged him to dry lands.

"Wake up, wake up, wake up," the merman said urgently as he shook Izuku.

Katsuki thought he was above this, saving strangers from peril like a hero, and yet look at him, flopping like a disaster to save one stupid selkie. He was making the same damn mistake.

Izuku weakly lifted his head and looked at him groggily, and Katsuki used this opportunity to keep him awake. His cold, clammy hands slapped against what he assumed were the seal's cheeks. Izuku groaned as he brushed against his whiskers.

If this wasn't a stressful situation, Katsuki would have taken the time to feel them, measure how long they were in his fingertips, but this was dire. He shouldn't be wasting time pondering over whiskers. Time was of the essence.

"C'mon, c'mon, c'mon," he whispered.

He felt sorry as the selkie groaned pitifully, but he had to drag him away from the ocean to do what he needed to do. Izuku left a trail of blood in the sand, but that was a minor issue. After all, the ocean would wash it away in due time.

The heat of the afternoon sun was hot, but at least there were no humans in sight since Katsuki had the foresight to swim to a secluded area where humans seldom roamed around.

Once he made sure Izuku was comfortable, he then instructed, "Peel off the coat."

Izuku's breathing was heavy and harsh. He exerted himself to reach land, and that effort took a toll on his body. However, hearing Katsuki's words made him eerily silent to the point that the merman feared the selkie breathed his last.

"Let me help you," Katsuki told him, earnest and true. "It'll help if you took it off."

It was easier said than done.

He knew the importance of stripping off the coat in front of another, the intimacy the action held. To undress and bare themselves in that position was reserved for family and lovers, and Katsuki was none of the above.

For a moment, Izuku bore his eyes into Katsuki's. Perhaps it was the blood loss or the merman's natural charm. Perhaps it was the way he mesmerizingly wormed his way into Izuku's thoughts, distracting him from his mission to find what was missing. Either way, Izuku has reached a consensus. He shapeshifted back into a human.

The experience was like no other. It was hard to describe it in words. Rather, it was easier to describe what it wasn't. It was not like taking off a tight bodysuit or peeling off layers of clothing. It was not like unwrapping a scarf or slipping off a thin layer of stockings.

Izuku was one with the coat, and the coat was one with him. Parting from it was like parting a chip of his soul, and though the excruciating pain was not a corporeal, it went beyond that.

The transformation was complete, and Izuku held his coat close to his chest to preserve a modicum of modesty. He felt naked, exposed. Normally he would have a stack of clothes by his side to change into, but here, there was nothing. There was only Katsuki.

A light pink blush dusted his cheeks, but his silence turned into a hiss as the coat shifted his leg. Blood seeped into the sand. The wound itself look gruesome, and the flesh seemed damaged and irreparable.

Katsuki grimaced.

Then his eyes trailed to the selkie's arms. With his help, the wound would only leave scars, just like the ones on Izuku's arms. However, he stared at the scars on his arms in concern because scars like that don't come from natural occurrences. Scars like that come from abuse and with the intention to leave them behind as a reminder. He wondered if they were caused by humans.

Dwelling upon those scars were maddening. He chose to distract himself and lifted Izuku's leg closer to his face. The action slightly jostled his leg and caused the selkie to hitch his breath sharply. The sudden sting brought tears to his eyes.

Sure, he had a considerable high pain tolerance, but as a reminder, he was just mauled by a shark. He had a good reason to complain since a portion of his leg was chewed up.

Tears appeared at the corners of Katsuki's eyes, leaking out until they slid down his cheeks and dripped into Izuku's disfigured ankle.

Izuku's voice wavered, his words getting more and more slurred.

"What are you-"

What happened next was plain magic. His leg was illuminated and enveloped by a soft orange glow, and this process continued for a couple of minutes until Izuku felt the telltale signs of healing. Little by little the flesh repaired itself as if an invisible thread stitched his skin back together. The sensation sent tingles down his spine and ignited fire in his veins. It felt warm, comforting, and safe.

Izuku closed his eyes, relishing this magical moment, and shuddered as the merman rubbed his arm with soothing strokes to ground him, remind him that he was here for him. For that, Izuku was grateful.

He wondered if everyone who was fortunate enough to experience mermaid tears felt like this as well. Katsuki was beautiful like this, crying crystallized miracles into his very being. There was a sense of joy that overwhelmed him. It was like sunbathing out by the beaches in his seal form, except that the heat from the sun was contained in his chest.

"Thank you," he said in a warbled voice, tired and weary.

Katsuki wiped away the stray tears at the corners of his eyes and brushed back Izuku's green strands. In turn, the selkie pressed his sweaty forehead against his palm as thanks.

Katsuki reminded him of the first time he poked a giant sea green anemone when he was a little pup. One touch, and they both close themselves from the world. However, Izuku was patient, persistent, because when something strikes his curiosity, he latches onto the object of his attention like glue.

The adrenaline rush gradually subsided, and Izuku let out a heavy sigh and relaxed. His eyelids were heavy, but he cannot afford to sleep at the middle of nowhere.

Katsuki glanced at the selkie's leg, newly healed and unblemished besides a few jagged scars that ran from his calf to his heel. Then he redirected his eyes to the soft gray pelt he discarded at his hip, a beautiful dappled coat that looked soft to touch.

Katsuki bit his lower lip.

He was no backwatered individual who was clueless about the social cues of a selkie shedding his skin in front of a stranger. It was scandalous. Yet, this was a monumental gesture of trust, and though Katsuki wished the selkie removed his coat for different circumstances, he had to make this right. He owed it to him.

"I'm not done yet," he said, still gripping his ankle.

Izuku blinked. "What do you mean?"

He simply wanted clarification, but his answer came in the form of Katsuki's breath fanning across his ankle. Before he could register what was next, sharp canines pierced his skin. Izuku gasped as a pleasurable jolt skimmed down his leg, churning his insides. The bite was deep, enough for the merman to draw out blood.

A whine escaped Izuku's throat as he clutched his coat tighter, bunching the fur around his fingers. He felt the burn; it was if the merman plunged his leg into a molten sea of lava. He squirmed, the instinctual need to pull his leg away overcoming his need to stay close to Katsuki, but the merman held his leg tighter in anticipation of this reaction. Their eyes held in a gaze, their hearts aflutter with only Izuku's heavy breathing to fill in the silence. It felt like eons until Katsuki let go, his tongue lapping at the remaining beads of blood, the selkie's coppery taste flooding his senses.

His thumb swiped against the mark on Izuku's ankle. He hummed a pleasant sound. Izuku watched in fascination as Katsuki brought his thumb to his lips and licked away the last traces of his blood. The bite mark glowed bright and true, eventually shaping itself into an orange-colored cross on the back of his heel. A flash of possession shadowed Katsuki's face, but that can't be right. It must have been a trick of the light.

"There," he said. "All done."

Izuku dropped his coat at his side, bent over his knees, and traced the outline of the cross with his fingers. He gently brushed against it. Only a dull ache was left. The searing pain he felt was gone.

"It's my mark," Katsuki explained before the selkie could question him.

"Why?" Izuku asked.

He was lost, but then again, he was always lost.

He was lost when he abandoned his son, leaving him to fend against the world for seven years. He was lost when he returned to the sea, for he was reminded again of the lonely nature of selkies and their tragic fate. He was lost when he met Katsuki and his pretty red eyes, forever straying him further away from his search.

He was lost and searched for guidance.

He was lost and found Katsuki instead.

In a moment of softness, Katsuki reached over and brushed away the selkie's bangs, tucking away some loose strands behind his ear. Izuku stared at him with eyes as wide as dinner plates. Realizing what he had done, the merman coughed away the awkward air between them. He forgot that he was caught in the moment, but there was nothing wrong with grooming the selkie's untamed hair. It was so messy and unkempt. It was worse than a tangle of seaweed. The selkie was practically asking for his help.

"Selkies are powerful," Katsuki said.

Stories of vengeful selkies reached far and wide, for even though they were gentler than merfolk, their rage was legendary. People drowned for their mistakes. Landscapes changed when they met with their fury. Katsuki knew better than to mess with them.

"But," he paused, "They're not invincible."

The incident today attested to his statement.

Izuku hummed as he clumsily stood up with sea legs. His coat wrapped around his torso like an overgrown towel to give him some dignity rather than flashing his junk. After all, he doesn't want to be known as a nudist to the locals here. He already got strange looks from the year he resided here.

"Well, thank you for your concern," he voiced his gratitude.

An honest smile lit up his face.

His eyelids were half-mast. "But…" Izuku licked his lips as he tiptoed his words. "Doesn't this mark," he said and lifted his leg to give the merman an unneeded view of his ankle and more skin, "Doesn't this symbolize that I'm yours?"

The selkie was coy. He knew what he wanted. Katsuki's tail thumped against the surface of the water in embarrassment. The merman felt like pulling his hair out of their roots.

"Don't get any wrong ideas!" he said hotly and averted his eyes.

Izuku poked his tongue through his teeth, amused. "What _should_ I think about then?"

"Stop doing that," Katsuki huffed and splashed water at the selkie's feet.

Though it would have been a small, petty victory, he hoped that he got the coat wet.

"Doing what?"

Cheeky little shit.

"This is only to protect you," Katsuki snapped back, "Since I enjoyed your company more than expected."

He clawed the sand and grinded his teeth. The selkie heckled him so much. He doesn't know why he was attracted to such a stupid selkie in the first place. The mark would glow at the face of danger. It was like a warning signal for whoever was foolish enough to approach Izuku and attack him. Any creature with half a brain would leave the selkie alone unless they wanted to incur the merman's wrath.

"It would be a damn shame," he continued, "If you died through natural causes like being shark food."

"I see," said the selkie, who crouched down closer.

"But, if you don't want it," Katsuki backtracked, "I can easily remove it and-"

He didn't get the chance to finish his sentence as the selkie tackled him to the ground. He burrowed his head underneath his neck, right at his collarbone.

"Thank you, thank you, thank you," he whispered, sweet and thick like honey.

The selkie closed his eyes and held on tight. He repeated his thanks like a mantra until it was the only sound Katsuki could hear. Though the merman does not fully understand the enormity of this gesture, it meant everything to Izuku because out there, it was a dog-eat-dog world, a place where nobody lent a hand and the losers had to fend for themselves.

Izuku was accustomed to that heartless, merciless world.

His instructions were simple. His fate was already laid out for him. Go find a widow. Get hitched. Return to the sea. Repeat the cycle again until his untimely death.

He had forgotten that he was no slave to his biological instructions, that he had the freedom to choose a different path. His eyes flickered to Katsuki, this wonderful, grumpy merman who was too good for his own good. He knew what he wanted to pursue.

They were chest to chest, skin to skin, as Katsuki tried his best to wriggle his way out of the hug because that was not a tail rubbing against his scales. However, it was a losing battle from the start. The merman eventually gave up with a huff and laid there on the sand with the selkie on top of him. Katsuki carded through the green locks absentmindedly as the selkie hummed in delight, rubbing his cheek against cushioned pecs.

This felt nice, he guessed, for Katsuki never felt this whole because no one bothered to care about him this much for centuries besides Mina. Katsuki wondered if he qualified as Izuku's friend, but for certain there was a connection, a profound bond they shared that they cannot simply ignore because here the two found solace in each other. Here they found another person who was just as lost as themselves.

"So, why were you fighting against a shark like a maniac, hm?" Katsuki asked to keep the conversation going.

Izuku, aroused from his dream-like state, peeled himself off the merman and lifted his head. Katsuki saw his pout.

"What makes you think I intentionally fought that shark?"

"You fought against me," he interjected.

Touché.

Izuku rested his head on Katsuki's chest once more and sighed. "My friends," he began, "They were in danger."

Katsuki quirked one eyebrow. "Friends?"

Izuku limply nodded his head. "Yes, my friends." He snorted. "My world doesn't revolve around you, you know."

Apparently, the merman didn't take that comment too kindly as he slapped his behind with a light smack. Damn, that ass was firm.

"Did you just-"

Katsuki gave him a smirk, and that was the perfect fuel to fan Izuku's revenge for his perky ass. The selkie scrambled to tickle the merman's underarms even though there was no concrete evidence that he was ticklish. He wrung out a couple laughs, some that sounded like tinkering bells, and stopped shortly after because Izuku was mesmerized by Katsuki's smile. It was more precious than any gem. It was brighter than any star.

Then Katsuki caught his wrists with a few stray snickers leaving his lips.

"Continue," the merman asked of him and batted his eyelashes to mock him.

Izuku jerked his head away to show he wouldn't.

"Please," Katsuki crooned teasingly and leaned forward to nip his cheek playfully.

Izuku pushed his face away with an upturned nose and a hint of a smile on his face. There was much coddling to be done before Izuku could relent since he wasn't _that_ easy. Eventually he did relent because he doesn't want to jostle himself too much. After all, he was still drained from the accelerated healing he just went through.

"I don't know what overcame that shark…" Izuku trailed off with a far-off look. The cogs in his brain were working, but something was missing. "My friends were diving today, so I was chaperoning them."

He felt bothered as he retraced his steps. He couldn't put his finger on it, but the shark seemed more feral, more out-of-control before Katsuki intervened. He assumed the shark was starving, but now that he had time to reflect, Izuku wasn't confident if his observations were correct.

"Then I noticed it was coming straight for us."

He warned Iida and Kirishima to disperse and reach dry land as soon as possible. The shark seemed crazed and full of bloodlust. Typically, they don't expend this much energy for a meager meal, but this particular one seemed fixated on Izuku. He was a fighter, but sharks were apex predators for a reason.

After that, the rest was history because then he realized one important tidbit. He shouldn't be here. He shouldn't be wasting his time mooning over a merman. Knowing Iida and Kirishima, they must have been worried sick for him.

He furrowed his brows.

"I should leave," he announced and removed himself from Katsuki.

His body was a traitor as it mourned the loss of the merman's inner heat, but Izuku was stronger than his impulses.

"My friends, they're…"

He combed his hair in distress. Even though it was still daytime, dusk was fast approaching.

"Oh no," he clicked his tongue, "And Oliver…"

Oliver was going to be upset if he doesn't see him.

Katsuki was quick to catch on. Though he was not a fan of humans, he understood the concept of friendship. He doesn't want to pry too deeply into earthly affairs, but he was lying if he said he wasn't curious.

"Oliver?" he asked hesitantly.

Uneasiness churned in his gut.

"Do you have someone…"

Izuku laughed. "Hold your horses there," he said and made some stopping motions.

Katsuki narrowed his eyes. "The fuck is a horse?"

The next second Izuku exploded into laughter, holding his stomach as he failed to contain himself. No offense, but his laugh was still ugly as fuck, and yet Katsuki was still captivated by the selkie's godawful snorts. He doesn't know what was wrong with him. No creature should fall for such cringeworthy laughs.

"A horse is," Izuku broke off and laughed behind his fist. "Sorry, sorry," he wheezed, "It's just-"

Then he laughed even harder.

Katsuki wrinkled his nose. God, why does he love that laugh? It's so ugly.

The merman popped his knuckles as the murderous intent to explode the selkie's cackling face radiated off him. Too bad he doesn't have the ability to do that anymore.

"You know what," Izuku calmed down and let out a snicker, "It's unimportant."

As if the fucker was aware of what his smiles did to him, he released a high beam one in his direction. It was deadly as hell. Overexposure could cause blushing, swooning, arousal, or all the above.

Katsuki was a brave soul to endure this much torture.

"But to answer your question," Izuku rubbed the back of his neck and smiled shyly, "No, I don't have someone like that waiting for me at home."

When he said that, he stared at Katsuki with a wily expression. It looked lonely, and the merman felt, in a horrified fashion he might add, a longing in his chest, the type that wanted to cradle his stupid seaweed head and comfort him with his melodious tunes. His fingers itched to hold him close. His webbed ears yearned to listen to his fluttering heartbeat. His mouth desired to taste… Taste what?

"Oliver is my pet," Izuku explained, unaware of Katsuki's inner combustion. "He tends to get clingy, and I don't want him to get stressed if I'm not home soon."

"I see," Katsuki replied, mind still perturbed by his carnal thoughts. He then asked, "Can I see you again?" He might as well initiate their meeting this time instead of accidentally stumbling into each other.

Izuku gave him his signature smile. The tail ends of his coat pooled around his feet as he slipped into it.

"Yeah, I'll come if you cry seven tears into the ocean," he said with a wink.

Katsuki rolled his eyes. In the lore, if a maiden cried seven tears into the sea, it would beckon a selkie. What a lame response. It was so lame that he rolled his way back to the ocean without a farewell, without even calling Izuku out that that trick would never work for him.

* * *

A routine began to form as Izuku and Katsuki solidified their friendship. Every morning Katsuki would perform his duties and socialize with the other mermaids. Occasionally he would be involved in some scuffles, but most of the time he would return to the shore unscathed where he would meet Izuku at the rendezvous, the place where Katsuki healed Izuku with his tears and granted him his mark.

Every late afternoon the merman would bestow him gifts, mostly in the form of squid and other sources of food. Izuku felt pity for the squad of squid laid at his feet.

He nudged one with his foot. "You don't expect me to eat all of this, right?"

"You're a seal," Katsuki stated the obvious. "You eat a lot."

Admittedly, seals can eat up to six percent of their body weight, which would estimate to an average of 50 pounds, but that need doesn't translate to his human form. His diet as a human was balanced and healthy.

"You don't like it?" Katsuki questioned, his tail flicking nervously in the water.

Izuku kneeled on all fours and began scooping the squid into a plastic container he brought with him. The first time Katsuki surprised him, he turned red as he hauled a year's worth of salmon on his back. People looked at him as if he was some fishy character. Yes, he was very fishy, but he wasn't suspicious.

"I do," he told Katsuki and glanced at him with a soft expression.

It would be impossible to consume all this squid. Perhaps he can share this with the neighbors.

"Good. You better," Katsuki puffed his chest and crossed his arms. "Took me at least an hour to gather that many."

Pride swelled within him. Izuku almost smeared squid juice all over his face before he placed his cheek on his hand. Katsuki was cute when he was like this.

"Never knew you were fishing for compliments," he joked, his tongue poking between his teeth.

Izuku blocked his face with a grin as Katsuki splashed saltwater into his face, but not before Izuku snatched a peck on the cheek to thank him.

* * *

The sea, it calls him, beckoning him to come home. It pulls him, grabbing hold of his soul and tugging him back to the water.

He tried.

He tried to resist that pull, fight against it with every fiber of his being, but he lost. The loss he felt was great. The loss he felt was too much for him to endure.

He cried as rivulets of blood marred his arms. He cried as he failed to hold onto what was important with these useless arms. He was weak, oh so weak.

He woke up with tears in his eyes and a scream begging to leave his lips. He ran to the beach, frantic, with his coat on his shoulders.

"Katsuki," he croaked and cried out pitifully.

The sting of his failures left him cold. He doesn't want to be alone. The worst part about being lost was the solitude.

The mark on his ankle glowed, a beacon of light in this dark and dreary night. Katsuki woke from his slumber and hurriedly broke the surface, his head swishing around to find him. Izuku was already a seal as he pounced on his back, rubbing his whiskered face between his shoulder blades as his weight made the merman collide into the bedrock. Katsuki's back was wet, and it was not because of the swim he just took.

Katsuki rolled around and patted Izuku's head. He shushed him. "It's going to be fine," he promised him as he guided his flipper to the deeper parts of the ocean.

Though he doesn't know the circumstances, though he doesn't know what Izuku lost, he understood the ache. He understood the hollow, crushing feeling of losing something that was cherished. It was a common thread among their kind.

"Let's go for a swim," he said because that was what they needed, to run away from the pain as much as possible.

For the rest of the night, that was what they did. They raced each other until they were exhausted and fatigued, until Iida found Izuku almost naked at the ocean bank, panting heavily from overexertion. Izuku was a lucky man to have such trustworthy friends, people who were willing to keep his secret to the grave. Though Iida was not there to see Katsuki crawl his way to the shore with Izuku in tow, he managed to catch a glimpse of a red, glimmering tail disappear into the horizon.

* * *

"You're here earlier than me."

Izuku removed the lid of his bento box, releasing the spicy aroma of his lunch to the unsuspecting merman. He flopped closer, curious, as Izuku used his chopsticks to offer him a bite.

"Taste some," he said. "You always got me something. It's about time I return the favor."

Katsuki scrunched his nose. "I'm not eating that."

"You won't know until you try."

"It's looks like you mutilated a bunch of eels with their blood."

Eating raw eel blood was poisonous for the average human, but that was beside the point.

The selkie defended his cooking. Sure, he was not a master chef, but his home-cooked meals were edible. "It's stir-fried noodles and vegetables with hot sauce."

He slurped his noodles slowly, eating them with fervor until his cheeks were puffed, to demonstrate that the noodles were safe to consume. He smacked his lips, his tongue peeking out to catch the sauce at the corner of his mouth. His advertisement pitch was quite persuasive.

"Just one bite," Katsuki compromised.

"One bite," Izuku nodded.

"Then you'll stop trying to feed me weird shit."

A heaping portion of noodles were centimeters from his face, pressing against his lips with gentle prods.

"Say ahh," Izuku cooed as he fed the blond his concoction.

Katsuki unwillingly opened his mouth and ate it, chewing it slowly to savor the taste. His mouth bursted with flavor and heat.

"Well?" Izuku asked, expecting him to scream bloody murder and dump his head into the ocean to wash away the spicy flavor. However, it backfired as Katsuki scarfed the down the noodles, eating it like a ravished animal until he licked the box clean. Tuna was good, but god damn noodles never tasted so delicious.

"More," he demanded, barely swallowing the rest.

He pushed the empty container to Izuku's chest. Flabbergasted, Izuku closed his gaping mouth.

"That was my lunch, you ass."

"You can make more," Katsuki replied.

Izuku puckered out his bottom lip. Katsuki returned him an impish grin.

"I barely got a taste," Izuku muttered.

Before Katsuki could tell him to suck it, the green-haired man took a literal approach. His hands reached around the back of Katsuki's neck, his nimble fingers tugging his strands with a fierce grip. Katsuki hissed by the unexpected force, but he welcomed the sting because he was caught under Izuku's spell, could feel himself freeze under those haunting green irises. The selkie could smell the faint spice from his breath.

"I worked extra hard making that," he whispered and took Katsuki in with a kiss.

Katsuki made a sound as he gripped Izuku's shoulders and trembled as the man parted and licked his lips apart with his tongue. He made a ravenous sound, one that went straight to his groin, as he explored the crevices in his mouth, tasting what Katsuki tasted, learning where he began and where he ended. He was addicting. He was fulfilling. He was too much.

Izuku parted from him abruptly, a thread of spit still stuck on his crimson, swollen lips. He touched them gently, embarrassed that he got engrossed with the mood. How unbecoming. He thought he was better restrained than that.

"More," he heard.

Izuku stilled.

His ears buzzed. The selkie had forgotten. The voice of a mermaid was infamous for a reason.

"More," Katsuki told him with a low timbre, eyes ablaze and hungry.

Izuku felt compelled to lean close, to feel, to taste him again until it was all he knew. Katsuki fixed the problem and closed the distance between them, his hand on the small of his back until their bodies slid together perfectly. He pulled backwards, back to the sea, back to where they belonged. Their hearts stuttered, quickening as their mouths melded again and again and again. Izuku's nails bit into his skin as he deepened the kiss. Katsuki returned the gesture with nips on his jaw, pausing to only hear Izuku hitch his breath whenever his teeth dug deeper than imagined. Katsuki never felt so full, so complete. He hoped Izuku would never let go.

Alas, that was how he would break, but unfortunately, that was another story for the future.


	3. Chapter 3

"I'll fucking kill you!"

"Katsuki, no!"

Izuku hooked his arms around the merman's shoulders before he lunged and swiped off half of Kirishima's face. The blond snarled, his tail flicking violently as he elbowed Izuku away and pounced once more.

"Katsuki!" Mina shouted and dived in front of her lover.

Katsuki halted in his advances. He doesn't want to harm her.

"Stop!" she screamed at the top of her lungs with tears streaming down her cheeks.

Katsuki stopped, not only because he doesn't want to hurt Mina, but also because he stared at her legs, her pearly, pristine legs. He made a pinched face. They were human legs. He hated them, and though he struggled to accept, she made her choice. She made her sacrifice.

He thought it was odd when Mina wasn't bothering him for days. He assumed she took one of her impromptu trips and traveled around the world. She called it sightseeing, romancing the world and the wonders it had to offer, but he called it lazing around and wasting time. Then she proceeded to call him an old coot for that. Whatever. Katsuki wasn't too concerned about her whereabouts because Mina was a tough cookie. She could handle her own tail.

Then he saw her this morning, hanging onto a redhead by the arm with a bright smile on her face. Maybe he recalled Izuku introducing a human to him, a man with hair as spiky as the sharpest sea urchin in the sea, but Katsuki doesn't care, not even if he was the nicest human being on the planet. He was human, and he took Mina away from her home.

The flames of hatred were alit. His cold-blooded veins ran hot. He rushed to Mina's lover with the intent to kill, or at least wreck his face to the point of no return, adding more damage to the small gash on his eye. He was livid; he was enraged.

When Izuku held him back, they thrashed against each other, with bites and scratches and pulls. Nothing could quell the tumult in his mind. Nothing could save him from this blind fury.

However, he was proven wrong as Izuku took his hand and gripped his wrist until it was stable and locked. He placed it on his neck and allowed his razor-sharp nails to gently rake through the junction between his Adam's apple and sternum.

"Hurt me," he dared him with a tremor in his voice.

Izuku's last resort was this. If Katsuki wanted to kill Kirishima, then he would have to kill everything he loved.

"Do it." He bared his neck to prove to him that he was not joking. "Because you have to go through me to kill him."

Katsuki yanked his hand away, horrified by the prospect of that. Izuku looked behind his shoulder, silently pleading Mina to hand him his coat, which was by the shore near her feet. Understanding his request, the newly turned human fulfilled his request and gently rested it on his shoulder. He doesn't mind its weight, for he would be one with it soon enough.

Really, Mina was such an innocent being, unhesitant of his order to hand him his coat even though that gesture was inadvertently known to be a proposal. He smiled. With a personality like that, no wonder Kirishima was smitten.

The selkie undressed himself slowly and allowed Katsuki to watch him, to help ease his raging heart to taper off. He laid himself bare, unafraid of showing his nudity to his friends. Kirishima and Mina averted their eyes as a form of respect because they knew what came next.

Izuku took Katsuki's lips and drove themselves to the bottom of the ocean as he transformed from a man to a seal. He held him as best as he could while Katsuki shook under his nuzzles, wept out his woes, and cried out his bitterness until he was ready to tell Izuku his short but miserable tale.

Most stories started with "once upon a time".

Therefore, Katsuki's story began like that as well. Most stories also have a conclusion, but lest did he know, Katsuki's story hasn't ended yet.

* * *

Once upon a time, Katsuki was a young merman who fell in love. He was not even half a century old, but he was so sure of his first love, so confident that it would last forever, that it never occurred to him to second-guess himself. He was inexperienced with the complications of love, but at the moment, he was in love. He was willing to sacrifice anything for this love.

Shindou was his name, the key to his heart, and Katsuki was attracted to him like a moth to a flame. It was mere coincidence that they met. Katsuki was exploiting his gift, creating wave-inducing explosions to hunt for food. He wanted a dynamic twist to his eating habits.

Shindou was there on his boat, amazed by his sheer power, and Katsuki knew he was special, wearing fine silks and jewels that glittered under the overbearing sun in broad daylight. He must have been a higher-class citizen, a noble of his society, the top brass of the pyramid. His voice was as smooth as slate. His smile was simply earth-shattering.

What intrigued Katsuki most was his reaction, the way he insensitively asked him, "Oh cool, a mermaid. Quick question: How do you guys excrete waste?"

His expression held childlike wonder, but there was a glint of something more.

Looking back, Katsuki wondered if he smashed his head into the rocky shore when he was just a little squirt. Why else would he be attracted to strange men who approached him with weird questions? After all, Izuku was practically hopping on the balls of his feet to get eaten by the likes of him.

Well, he wouldn't mind eating Izuku, but that's for another time and another place.

Beneath Shindou's sunny personality was a kindred spirit. The darker, corrupted parts of his soul made Katsuki like him even more, for though he was intelligent, open-minded, and easygoing, he was also greedy, selfish, and stubborn. He said it proudly as if he gloated about some ornate handiwork he commissioned last month.

When Shindou dropped the nice act, Katsuki felt special. When Shindou returned and visited him every week without fail, he felt as if they were something more. The man would come back bearing gifts and knowledge of the outside world, and for Katsuki's ever-growing curiosity, the noble satisfied him with more trinkets and stories to share.

One private evening, Shindou confided to Katsuki about his dreams. "I wish to travel the world," he said as they laid their backs against the sand, with the ocean tickling his feet and lapping against Katsuki's tail.

His skin sparkled and shimmered underneath the moonlight, though nothing could compare to Katsuki's iridescent scales.

"It's not much," the merman shrugged. "There are slight differences, such as climate and food, but humans are still humans. The sea is still the sea."

"But you never traveled land. How would you know?"

"I don't need legs to travel the world," Katsuki huffed stubbornly.

Shindou laughed and flicked a speck of sand onto his companion's collarbone.

"You should," he said. "It would be nice," he reached out his arm towards dotted sky, "If we could travel the world together."

They were harmless, careless words, but that was enough to push Katsuki to the edge and struck him to his downfall. Even though they knew each other for months, that was enough time to form a connection. It was enough time to fall in love. Katsuki latched onto that emotion like a symbiotic organism, and immediately he set out to achieve Shindou's dreams.

The sea witch was a creature one would avoid unless they were in dire straits. He traveled far and wide to meet this particular one, for he was known to be the most powerful of them all. Even though wishes came with a hefty price, Aizawa was reliable and direct. He was no trickster, and he would never mislead his clients to doom.

Rumors said he gained that reputation when he had a lover because he wanted to share that happiness. One day his lover vanished, and all that was left of Aizawa was a shell of his former self. Still, he was considered the kindest sea witch out of them all, for only the loneliest people could be so kind.

However, that does not mean any client was invincible or impervious to the magic that sea witches used. Oftentimes it was the wishes demanded upon Aizawa that brought his clients to an early death.

"Make me into a human," Katsuki ordered once he entered the sea witch's cave.

Aizawa was curled in his tentacles and cracked open one eye from his slumber. The long tendrils of his hair covered most of his face and camouflaged well with the backdrop of his gloomy, depressing home. He uncoiled himself from his inky, black tentacles and stretched himself to his full height.

"What brings the young prince of the sea to my humble abode?" he questioned him lethargically.

The cool temperature of the cave brought frost to Katsuki's lips. His hands twitched to spark off the explosions of his gift.

"Make me into a human," Katsuki repeated his request. He paused for a heavy second. "Please."

He needed to be in Aizawa's favor to be successful. He thought of Shindou and his stellar smile. He thought of how happy he would be once he sees Katsuki's legs, how much the merman sacrificed to travel the world and know everything and anything.

"Are you sure about that?"

Though he asked, the sea witch went into work and went to his storage to gather the necessary ingredients.

"Yes," Katsuki swallowed. "I am."

Aizawa sighed tiredly. The sallow bags under his eyes were more pronounced. "I see."

"What is the price?" It was time to get straight to business.

"Nothing, really," Aizawa murmured as he crushed the necessary materials into a dark velvety paste.

"Nothing? Impossible." Katsuki swam closer and hovered over the sea witch's shoulder, watching him work out the finer details of his potion. "There's always a catch."

"You're not wrong."

Aizawa stopped grinding the shells and stared into Katsuki's red, burning irises. He was so young. He doesn't know the pain of lost love.

Then Aizawa stated, "The sea is a part of you, and you are a part of the sea."

The sea witch circled around a rocky structure that was rooted at the center of his cave. It looked ominous, creepy, as if it was made from dead coral, bones, and other stringed organs. There were misshapen pieces protruding out from the edge, and Katsuki made sure to avoid touching it.

"This transformation _is_ your price," Aizawa said. "Taking any more would be overcompensation, for you are already sacrificing who you are."

Katsuki still wore a befuddled look.

"You will find out why it had to be this way soon enough."

His cryptid words sounded like a warning.

Using the structure, he created the potion and made Katsuki consume it. Light engulfed the merman, and he smiled as the sensation tickled him and crept up his spine. The split was made at the middle of his tail, and it was fluid and quick. The transformation was done, but it exhausted him to the point of blacking out. When he woke up, he found himself at the shore, naked and with a new pair of human legs.

The first hour was a struggle because he had to practice how to balance with his two legs, but once he got moving, he gathered some abandoned sails and other material laying around that could substitute for clothes. He remembered Shindou mentioning how humans were prudes and had to cover every inch of their body. Katsuki thought it was a ridiculous rule, but he doesn't want to disappoint Shindou when they meet.

During high tide, they would converge at the sea cliffs. Shindou would typically gather rope and climb down its face, but today, Katsuki would see him at land before he got the chance to climb down. The excitement made him giddy. Katsuki couldn't wait and envisioned Shindou's surprise. A delighted shiver pushed him to move faster. Shindou would be pleased and show a little flash of teeth, the type of smile that Katsuki would like to make over and over again. Katsuki was almost there. It was almost high tide when he left the sand.

Katsuki saw a tuft of black hair at the horizon, and he smiled, ready to wave and shout and let his presence be known. He cupped his lips to do just that, but when he saw Shindou's full figure, he slowed. He stopped. He froze.

The world felt like it tipped over. The sun no longer felt warm and comforting. It felt harsh and cruel.

There he was, the object of his affections, having a picnic with a woman he never saw. Her hair, which she held up in a simple bun, was not a beautiful gold color like his. Her teeth, which she kept flashing to Shindou from laughing at all his jokes, were all crooked and exposed her overbite. Her voice was high-pitched and annoying, which was levels upon levels beneath Katsuki's sweet and melodious tune. Yet, while Shindou looked at him as if he was a special creature, someone worth knowing, Shindou looked at this woman as if she stole his heart, nourished it with love, and owned it for all to see. Katsuki was included as the audience.

He couldn't bare the pain, to stare at the love-filled exchanges they shared like some exhibitionist. Katsuki turned to leave. Now that he thinks of it, they were never exclusive, and he never bothered to ask the human if he had someone waiting for him at home.

He was stupid. He was stupid for giving up everything to have a chance with a man who would never love him.

He felt ugly. He felt ugly as he ran through the streets in tattered rags and knobby legs.

He felt foolish. He felt foolish for shedding tears for a love that never blossomed, that immediately withered and died once he saw Shindou kiss that woman. He felt even more foolish for wanting to replace that woman instead.

* * *

"He will pay," Uraraka hissed with a thunderous smack against the planes of the ocean. "That human will regret tricking you."

Katsuki was unresponsive to her venomous words. Instead, he dipped his toes into the shallow pool of water next to him and pondered over what would be his next course of action. He missed home. He missed racing with the other mermaids, hunting with his kin for food until their bellies were stuffed and stretched. He missed singing with them, enchanting any creature lucky enough to listen to their songs. He never knew how much he lost until he gave it up.

Tears pricked his eyes. He was miserable, but he was not shameless. He would never beg Shindou for help. He wouldn't. He shouldn't.

The mermaid sheathed a dagger out of nowhere. Depictions of serpents slithered around the metal hilt, covering it from head to toe. The blade gleamed beneath the sunlight.

"You can fix this," Uraraka said as she handed him the answer to all his problems. "I went to the sea witch for advice," she explained with fervor. "He told me that all you had to do was plunge this into the human's heart."

An electrifying spark ignited in her crazed eyes. "Kill him," she told him. "It would be a necessary sacrifice for you to return home."

Katsuki fancied that thought for a hot second, to erase the light of life from the human's eyes. He would get rid of the problem altogether. Even better, he would gouge out the woman's eyes and feed them to the fishes, cackling in the background while she defended herself pitifully against the horrors of a merman's wrath.

His frustration emanated in waves, crashing into his battered heart without respite. Despite the jealousy flaring within him, he couldn't. Not like this. He knew he couldn't.

"No," he shook his head. "This was my mistake," he flung the dagger away and watched it skipped a couple steps before it sunk into the ocean.

A series of explosions erupted from his palms, causing a ruckus that would surely attract attention sooner or later. Even so, he felt a bit better.

"I'm not so pathetic," he laughed darkly, "That I would kill him when it was entirely my fault."

Uraraka wore a pensive look, for she was concerned for her friend's well-being. "What now?" she asked him.

Katsuki stared at his reflection. His haggard, ugly reflection. Being human ruined his complexion. He saw his legs, the ones he gained while trading the sea away. Shame engulfed him and swallowed him whole.

He loathed himself.

Turning into seafoam would be a kinder death than this, the death of human with no ambition, no goal at the end of this journey. He wanted to disappear, to vanish. He cannot think of a life worse than this. Away from the sea. Away from who he was meant to be.

* * *

"So, you're back."

Though the sea witch does not like making house calls, he would make this exception. He groggily trekked his way to Katsuki, who was perched atop another boulder, legs held to his chest with red-rimmed eyes.

"Did you know this would happen?" the blond whispered.

He looked sickly and yellow, as if a gust of wind would blow him away.

"No," he told him. "I had an inkling, but no, I didn't."

Katsuki's solution was Aizawa, but the man was no longer the naïve idiot who would whisk away his tail and fins. He had grown into a heartbroken fool who wished to bargain for his identity back, and with it, a heavy price was given.

"I'm sorry," the sea witch apologized.

The price was to sacrifice his gift. Once he uttered those sacrilegious words, Katsuki went silent. His wind-swept hair covered his eyes, but Aizawa doesn't need to see him to know he was crying.

"No, please," his voice cracked. "Anything but that."

Arms outstretched, he stared at his hands. They shook uncontrollably. He cannot fathom a day without his gift. He cannot grasp the idea of losing the ability to make explosions.

"Without it, I'm-"

"Nothing?" The sea witch finished for him.

The young man nodded.

"It's your choice," Aizawa said forebodingly. "I'm sorry."

Shindou was not the main reason why Katsuki hated humans with a passion, but he was the start of a list of humans who wronged and took, who corrupted and ruin. There were too many stories, too many instances of the damages humans caused. There were stories of mermaids who made the same fatal mistake as Katsuki, who were thrown into the wolves and raped from the ones they trusted. There were stories of kappas who were forgotten and displaced, who had to watch their homes be destroyed in front of their eyes. There were also stories of sirens who were experimented and probed, who were violated to the point that their vocal cords could no longer work due to the trauma.

They polluted and brought the destruction of wildlife. They caused wars and grief and sadness. There were so many stories. There were more stories than the number of scales Katsuki had on his tail. He doesn't know if he has the capacity to forgive humans. He doesn't know if that day would come.

He can tolerate a select few, but that was the best he could do.

* * *

Izuku held him as he finished, even when the seal himself was beginning to deplete his oxygen reserves.

"Thank you for telling me everything," Izuku transferred those thoughts to Katsuki in his seal form.

If he was in his human form, he would have shed emotional tears, for nobody deserved to make that choice. Sacrifice was never an easy deed.

Yet, Izuku still doesn't know the full story, the finer details of Katsuki's torment. Someday he will tell him. Someday he will know.

Someday he will tell him the other reason why he wasted his first hour as a human, how walking through the coarse sand felt like walking on knives, how it felt like blades were cutting through his skin with each painstaking step. Someday he will tell him how the anticipation of seeing Shindou lessened the sting, how that pain was amplified tenfold after he gave up on the human. Someday he will tell him how close he was to turning into seafoam, how the wind felt promising as he stood at the peak of a cliff, ready to dive and fall and accept his fate.

He knew what it was like to swim in the ocean and walk on land; he might as well learn how to fly in the sky.

* * *

Humans were laughable creatures. When it came to matters of love, they hesitate and wait before they professed their love, as if _they_ were the species that could live for centuries instead. For Katsuki and Izuku, they knew better. They knew what forever felt like, and forever doesn't exist. Forever could just end with a snap. They learned that the hard way. They learned that through hardship.

That was why they openly loved, for love was better said than never said at all.

* * *

"I love you."

Katsuki flickered his eyes to where Izuku stood, surrounded by precious gems and other rare treasures, but they seemed lackluster compared to him. Here was where the merman stored his jewels and other remarkable findings. Here was where he felt most safe, for even though he can never regain his gift, these materials filled in the cruddy gaps.

He discovered this place by accident. Some would call it a cenote due to its sinkhole-like appearance. The roof was open and clear, and moonlight washed over his features, giving him a heavenly glow. To Izuku, he seemed more like an angel than a merman with a hot temper.

Izuku crouched down until his head hovered above Katsuki's.

"I love you," he repeated.

"I know," Katsuki replied in earnest.

Izuku lowered his head.

"I love you," he mouthed over and over again, peppering soft kisses on his forehead, his cheeks, his neck, and wherever his lips guided him.

"I know," Katsuki shuddered as Izuku's hands rubbed his sides, teasing against the seam between his skin and his scales. "I love you, too," he said quietly, for those words were only meant for Izuku to hear.

* * *

"Truce?"

Katsuki met stupid humans before. For example, he witnessed this one human who got capsized and denied every form of rescue because he was waiting for some holy deliverer to help.

The poor sucker died of course.

This, however, this human was insanely stupid. Kirishima, Mina's raison d'etre, knelt by the shore and offered the merman his hand to shake. He listened to half of what he said. Something about wiping the slate clean or shit like that.

His pudgy fingers were centimeters away from his mouth, so logically, Katsuki attempted to chomp them off and snapped his mouth shut.

Kirishima yelped as he retracted his hand. Katsuki's teeth clacked together.

"Tsk," he clicked his tongue.

The human was fast. He would give him that.

"Hurt her," he hissed, "And I will feed you to the fishes."

He sunk and lowered his head into the water until the top half of his face was visible. Izuku was a strange one, befriending dumbbells like this one.

"Ha, Ashido always mentioned that you had a sense of humor," he smiled widely.

Katsuki bristled when he used her first name.

"Don't worry," he pounded his chest as if he was a deranged ape, "I won't hurt her."

Then he added, "Besides, it would probably be more accurate to say that she would hurt me first."

"What?"

At first, Katsuki was confused because Mina was too loyal to throw this human away like a used shellfish. She was head over heels for him, heart eyes and all. Yesterday she gushed over her beau for over an hour, destroying his ears as she went over intimate details of her love life and the extraordinary opportunities human life provided her. Katsuki was not jealous, but he was not overly happy either.

It was a weird limbo to be in.

Katsuki was no longer confused when the redhead turned around and flashed the nape of his neck. Due to the low cut of his collar, scratch marks, the ones that dig deep and draw out blood, were scattered all over.

The merman turned a shade of pink and snarled as he hauled his body out of the water. He wanted to get another swipe against this infuriating, happy-go-lucky human.

He hated this. Mina was so happy.

They were perfect for each other.

* * *

One night, Izuku invited Katsuki to stargazing. It was odd, considering that there were no fireworks scheduled today, but Katsuki agreed regardless. There was no other occasion to watch the stars, but seeing Izuku, kissing him, having him close, was open for any occasion.

When they reunited, Katsuki flicked his nose. "Stupid seal, you took too long. You always swim so slow," he said.

Izuku gave him a gentle smile. He floated on his surfboard, laid his back against the surface, and lifted his head to the stars.

"Let me tell you my story," he began in a hushed voice.

There was no outside activity in the ocean. There was only Katsuki and Izuku.

The merman followed his lead and floated beside him, gripping his hand tight as Izuku unraveled the events that happened before their encounter. Before he could, Katsuki caressed his arms, his webbed fingers tracing the scars that damaged his arms.

"Will you tell me what happened to them, too?" he asked.

"Yes," Izuku answered him, "But it's not what you assume."

There, he told him a truncated version of his tale.

His story was a classic selkie one, though it happened far too often of his kind. He was careless, like any other selkie, and was caught by a human. As usual, he attempted to steal the heart of a widow and make her his. He succeeded in capturing his latest prey, but when she saw his true form, the tables have turned. She snatched his coat when he removed it and forced him to marry her.

Izuku had to be complacent to her terms. If she damaged or burned his coat, he would die, so with his limited options, he chose the safest route and married her. He pleased her to get in her good graces. He made an offspring with her in hopes to placate her needs. He doesn't hate her, but at the same time, he never truly loved her. Rather, he was detached to the whole arrangement. Hell, he loved his son more than the mother, but no matter. He would simply wait for her to waste away and die like any other human. Then he would return to the sea, for it calls him. It always calls him.

However, his plans were quashed that one evening. The woman was out on a grocery run, so Izuku was left in charge of their home and their child.

Izumi was the sweetest child. Izuku loved him ever since he laid his eyes on the baby and held his bundled form right after the birth. He gained his mother's hair and eyes, but his smile and good-natured personality was his. He was a selkie through and through, and Izuku was giddy with excitement, ready to teach his son the language of the ocean, the laws and rites of his birthplace once he was of age.

Since his wife was out, he played the role of a good husband and lessened her workload. Even though he was out here against his will, the woman was cooperative and kind. He knew she would come home bedraggled from her 9-5 job, and he appreciated the effort. He was dutiful as he cleaned the house spotless, so he never guessed that he would come across his coat again. He never guessed that this would be his last night with his son.

The boxes were tempting. They recently moved into this house, so his curiosity got the best of him. He rummaged through them, thinking that they held photos and other frames he could hang up against the walls.

He froze when he saw his coat, his beautiful spotted coat.

Though he never stopped looking for it, his campaign to search for it weakened after the birth of his son. He wanted to concentrate on parenting, on nurturing and nourishing his son until he was old enough to understand his heritage.

He knew what came next. He braced for it. Usually he wouldn't. The process was much simpler if he accepted his fate, but this time he had to fight. This time he had to resist.

The call of the sea rang in his ears, and it moaned in his heart. The call overwhelmed him, seized him, and punched him in the gut. It was so powerful, so strong to the point where he collapsed on the ground and keened out of shock.

Go home, it told him. Leave at once, it commanded.

"No," he whimpered against his instincts. "No," he said again with a firmer voice.

He helplessly clawed the ground and thought of his son to tether him here, but it was pointless. This, he knew.

No selkie was strong enough to power through the call, to resist the urge to return home, but he had to stay. He had to stay for Izumi. He refused to leave his son. Then another surge of pain crashed into him, rocking his ribs from the inside and splitting the crevices of his soul.

The sea, it calls him. It roars in his heart and punishes him, whipping him until he had to muffle his screams into his sleeve. He does not want to startle his son awake. He had to fight back until he could recompose himself in time. This battle kept going until he was tense and high-strung like a rubber band, daring to snap at a moment's notice. Izuku's psyche was stretched thin.

"I am the sea, and the sea is with me," he shuddered and clutched onto the side of the dresser.

Words held power. He only hoped that these words were enough. A few minutes, he told himself. All he needed was a few minutes.

"I am the sea, and the sea is with me," he picked himself back up and held onto the wall for purchase.

Tears streamed his reddened cheeks and dripped from his jaw. He overexerted himself until he was at his limit. He kept going until the regret blurred his eyesight.

"I am the sea," his voice wavered as he took heavy steps toward Izumi's sleeping form. He paused and took this moment to breathe. "The sea is with me," he strained out and let out a crippled cry.

The frequency of the noise in his head increased into a high-pitched, continuous screech. The impending migraine was inevitable, but he latched onto the pain and pursued after his goal. He was finally at Izumi's bedside, and he watched his son resting peacefully with a faint smile on his lips. The noise dimmed down, as if the sea could sense what he was going to do. It was a brief moment of privacy, but it gave Izuku the freedom to speak.

There was so much he wanted to do. There was so much he wanted to say.

He gripped the bars of the crib and lowered his head until he could see the soft puffs of air that escaped Izumi's mouth and the light rise and fall of his chest.

It was unfair. All of this was too cruel to bare.

"I'm sorry," he half-whispered and sobbed.

He pressed a watery kiss on Izumi's unwrinkled forehead. The short tufts of hair brushed against his lips.

"I'm sorry," he broke down, his shoulders shaking along with his frame.

With the last ounce of his control, he wiped away the tears and proclaimed, "I'll come find you."

Another kiss. Another regret.

"I promise," he said. "I promise…"

After that, he stiffened and let go.

The change was automatic, and his movements were robotic. A false sense of security was injected into him, but he was powerless against the ocean. He felt betrayed and wrong by his home. He felt like the lowest scum of the sea.

His finger pads caressed the fur of his coat, and the skin thrummed beneath his fingers, anticipating for the moment when they would become one. He walked out and never looked back. He abandoned his son and his wife.

The laws of the selkie folk were strict and precise. Whenever a selkie finds their stolen coat, they cannot return to land until seven years passed.

So he waited. And waited. For six, terrible drawn-out years.

* * *

While telling this to Katsuki, there was one minor section left unspoken. He would eventually tell him, but he was not ready to say it yet. After his failure to hold onto what was dear, he swam to Aizawa and attempted to negotiate the terms. Rumors said the sea witch fell in love with a siren, but due to their status, the siren was stripped of his powers and the lovers were separated for eternity.

Aizawa was well acquainted with lost love. Izuku wondered if the sea witch would sympathize with his cause. He immediately pleaded his case.

"Please," he begged and groveled. "Help me override these instincts. Please let me return to my son."

"You don't want this," Aizawa admonished him for such a careless wish. "The cost is too great. Don't make me do this."

"Anything," Izuku fought back. "I'll give up anything!"

The sea witch then replied, "Even your arms, the ones that couldn't hold your son?"

Izuku went tight-lipped. For a serious second, he contemplated that sacrifice. Desperation clouded his judgment but for good reason.

Selkies first present themselves when they are seven years of age, which meant that Izumi's coat would appear before him, urging him to initiate the rites and merge with his coat. Afterwards, he must dive into the sea to complete the passage. If he ignored the call of the sea or prolonged the wait, he would become sick and die.

After hearing the stakes, Aizawa advised him, "Come back after six years."

Izuku opened his mouth to protest.

"I cannot haggle the price to my own interests," the sea witch continued, "But you need to keep your arms."

He slumped into his seat. Izuku saw a sliver of the full extent of his exhaustion and pitied him.

"I have seen it all," Aizawa said with a melancholic smile. "You need to be mindful of the losses before you set your eyes on the gains."

It was irrational to shield one's eyes from the bigger picture. Izuku realized that, but it was a hard pill to swallow.

"Indeed, you are too kind for this job," Izuku said solemnly.

"It's a job I agreed to do."

Then he went into Aizawa's space and squeezed him with closed eyes and an overbearing heart. "I wish for you happiness," he said last and swam away.

"Me too," he replied and went back to sleep.

What Katsuki knew was this.

When Izuku returned, he set out to find his son. He bargained his arms and accepted the price as invisible claws slashed them until it cut deep to the bone. He bit the bullet and gritted his teeth throughout the process, for his tear ducts had already ran dry. This was the price, and he welcomed it with his now damaged arms. They would be slightly paralyzed for the rest of his life. His swimming speed would be slower; his strength would be downgraded. This was the price, but this was nothing. Nothing was more important than his son.

"You'll find him," the merman reached over and held Izuku close. He petted his hair and murmured words of support. "You will."

Yes, he would. He must.

They held onto each other like that, uninterrupted, as they licked away the wounds of their past.

* * *

Precious time was ticking away, and though Izuku assured Katsuki that his presence comforted him, motivated him to continue his journey, Katsuki encouraged him to spend more time to search for his son. There was always a sort of restlessness from the selkie, so now with the knowledge of Izuku's son, the pieces clicked into place.

He missed Izuku and longed for his seaweed hair and ridiculous laughs, but he would never forgive himself if he held Izuku back from a matter as crucial as this. At least the man visited the sea shore during his free time, albeit less frequently, but when he does, he would contact him with Katsuki's mark. The bond would tickle Katsuki and direct him to the source.

Today was just like that.

"What are you doing here?" Katsuki queried and noticed Izuku's jittery steps, the way he twiddled his thumbs when his thoughts were in disarray. His coat was at his feet, which indicated that they were going for a swim.

Izuku bent his knees until he was on all-fours. He leaned forward, eyes wide and lips parted. "I missed you," he confessed.

He looked so vulnerable and lost. Katsuki was lost in those bewitching eyes.

Three simple words, but they made Katsuki's heart lurch.

"Stupid seal," he croaked. Dammit. He missed him, too, but if he said it aloud, Izuku would never leave.

His body, however, betrayed him. His hand went to his cheek, and Izuku reacted to it and nuzzled against it with half-mast eyes.

"Take me to the cenote," he said breathily.

He wore a mint green short-sleeved hoodie and a terrible looking pair of swim shorts. Despite his horrid attire, Katsuki was drawn to him regardless. Izuku's arms wrapped around his neck and coiled around it like a prized necklace. He pressed his front against Katsuki's chest and slotted their bodies perfectly together.

"I need you, Katsuki," he gave him a chaste kiss, seducing him and breaking down his walls. He tilted his head and asked him, "Won't you heed my call?"

Izuku, he calls him. He calls him to take him and love him with every fiber of his being. There was no way he could ever deny him.

Katsuki peeled off his clothes in a rushed and hurried frenzy. Izuku was already there and connected his lips, humping into his tail as if he was possessed.

"Transform," Katsuki parted their mouths. "So then we can go."

Izuku nodded and took his coat. Newly transformed, Katsuki took his seal and swam as quick as he could to the cenote. Fortunately, their destination was close and safe.

The seal padded his way to the surface, and Katsuki observed, mesmerized, as Izuku transformed from a seal into a human. He could watch this a hundred times, and he would never get bored of it.

The reflection of the water made him beautiful, desirable. Katsuki felt inclined to devour him. There was no need for a strip tease or a show. All Izuku had to do was to sit at the edge and spread his legs.

Unashamed, Izuku pumped his cock and moved his hand to long, heady strokes. His thumb rubbed against the slit, and he let out a filthy moan, calling for Katsuki to hurry up and pleasure him. Katsuki caught his wrist and stopped him. His other hand sidled up his thighs, caressing the smooth planes of skin with a tenderness that made Izuku want to destroy it. Wreck it. To rip open and reveal the predator inside him.

"Katsuki, please," he whined. His inner thighs trembled as the blond blew the tip and grinned as the reddened head twitched.

"Patience, my love," he said in a playful manner and abided his time.

He sucked onto patches of skin until they blossomed into bright, purpling bruises. His nails teased the selkie and left pinpricks of blood, which he lapped with his tongue until Izuku began to rock his hips. With strong, trembling thighs, he maneuvered his legs and slipped them over Katsuki's shoulders. Without warning, he used his heels and pulled him closer until his face was right near his dripping cock.

Izuku was greedy. He just doesn't show that side often.

His fingers were fierce as they tugged his hair. He jutted out his lips, unhappy to not have that mouth on him yet. He waited too long. He pulled until Katsuki's head was snapped back, and the merman held his breath as he watched those radiant eyes demand him compensation.

"Suck," he growled with eyes ablaze.

Heat flushed the merman's face. He smiled like a minx to cover it up. He licked one stripe to calm his seal down, and then, just like Izuku kindly asked, Katsuki took in as much as he could.

It was a good call.

"Ah!" Izuku gasped and folded into himself.

Katsuki bobbed his head in a breakneck pace, sinking deeper and deeper into Izuku's cock until the tip reached the back of his throat. Katsuki shuddered and enjoyed the ride as Izuku held Katsuki's head and fucked into his pretty merman mouth. He thrusted into it, crying out in pleasure as Katsuki followed his rhythm to the best of his ability. His limbs clutched onto Katsuki like a lifesaver. Slick, squelching sounds filled the air. Izuku felt the arousal burn him until he was molten hot.

Katsuki hummed in delight and savored Izuku's taste. He took in more, mindful of his fangs, and relished in his lover's screams, cherished them as they echoed where they were. The vibrations from his throat was too much, and Izuku cried out as he orgasmed and spilled into his mouth. Katsuki was not finished. He was very thorough in his job. He gripped Izuku's pliant ass and milked him dry. He swallowed his cum and came off with a pop. Then he peppered everywhere with kisses and licked every bit he missed.

Izuku was sensitive, but he thanked Katsuki with stars in his eyes and fondness pouring from his lips. Katsuki hauled himself up and met Izuku in a kiss. He always enjoyed blowjobs. He liked the taste of salt.

They stayed like that for hours, making out and exploring each other's bodies until the sun rose and spoke of a new day.

Izuku loved Katsuki. He loved him so much. He doesn't know what it would feel like to live a day not loving him. He doesn't want to be a burden. There were too many stories of their kind being taken advantage of, of being expected to choose unfair choices for the sake of love. Katsuki was the sea, and the sea needs him. Even though Izuku yearned to be held, or to hold Katsuki in return, he will never ask Katsuki of this, to turn into a human and turn away from who he is. He understood his suffering. He understood how much choice meant to him.

Izuku loved Katsuki. He loved him so much. The sea, it no longer calls him, for Izuku was already there.


	4. Chapter 4

"Show! Show!"

"Yeah, yeah, I'm coming."

"Show! Show!"

"God, you're persistent!" Izuku laughed as he dragged away the curtains and unlatched the sealed windows.

Instead of revealing a beautiful landscape of the coast and the big, blue sea, a misty fog shrouded the town and only gave Izuku a hint of the bare, naked trees scattered around the area. Winter was coming. Two more days remained until it was Izumi's birthday.

"Show! Show!" the cockatoo squawked. He ruffled his tail feathers and leaned further out the window. "Show! Show!" he repeated again.

"Oliver, stop that," Izuku petted him with fondness.

Oliver was his first pet, and he treasured him as if he was his own coat. Life as a human was lonely. Izuku took up Iida's offer to buy a pet, and though he could have gotten a cat or a dog or a fish, when he made eye contact with the wallowing cockatoo at the time, there was a connection between them, a connection he couldn't identify. During the days Izuku felt homesick and spent his time in the ocean, Iida or Kirishima would babysit Oliver until he returned.

Speaking of Kirishima, he seemed to have brightened even more, like a sunflower basking in the sun, ever since Mina lived with him. They were a lovely couple, always visiting his home to perform karaoke or drink themselves silly. As expected, Mina was the champion of high notes, her singsong voice beckoning the men to drown themselves in her music until they realized they weren't at the ocean.

It was amazing how quickly their friendship bloomed. Izuku chuckled as he petted Oliver with a melancholic air and a wistful, ancient expression on his face. How many times must he learn the same lesson? He told himself over and over to be wary whenever he befriended ephemeral beings, and with Mina's permanent decision to be human, she aged alongside her lover.

He was going to miss them after they died.

The wind whipped his hair with a howl, and it slashed against his cheek, leaving him cold and shivering. He held his clothes close and shooed Oliver to hop back inside before the wind blew him away. He closed the windows with another shiver and grabbed his kettle to brew himself a cup of tea. He worked in silence, and it unnerved him, as if Oliver knew the state of disarray in his mind.

Two more days, he told himself with a sense of dread.

Two days felt too close.

However, Izuku saw Katsuki that same day, and nothing, not even the impending deaths of his beloved friends, could keep him depressed. Despite the blistering winds and the freezing waters, he needed to see him. He must. His heart ached as they embraced each other, Katsuki's fingers gripping the back of his sweater tight. His cheek rubbed against the crook of his neck, and they stayed there, scared and lost and afraid of the unknown.

"Tomorrow," Izuku said with a shudder, "I'll go see Aizawa."

Katsuki hitched his breath and pulled away with concern masking his face.

"Are you sure?" he asked.

His webbed fingers lightly touched his cheek, and by habit, Izuku lowered his face and pressed back against Katsuki's hand, relishing the merman's caress. He trembled, and as much as he would like to imagine it, it was not because of the cold temperature. Sure, some species of seals traveled south during the winter, but Izuku was a full-fledged selkie. A bit of cold water wouldn't deter him from having this.

Katsuki bit his bottom lip; the question left on his tongue. His tail swished nervously, understanding the purpose of this meeting. He also knew that discouraging Izuku from meeting the sea witch was not on the table.

Izuku's eyes flickered to the horizon. "Yes," he answered. The love he had for his son was never a burden even though he sacrificed so much.

His eyes then flickered back to Katsuki. He placed his hands on Katsuki's cheeks and kissed him, warmth traveling through his veins and salt coating his tongue. Their bodies were intertwined, bonded together in unbreakable ties.

"Please," Izuku asked of him and kissed him again to chisel the enormity of his request. "Come with me when I go see him," he said. "I don't want to be alone."

"I promise," Katsuki leaned forward and pressed his lips softly against Izuku's eyelids.

His heart was heavy, and he was afraid of the cost. However, Katsuki would be there through thick and thin. His presence would be the soothing factor Izuku needed to overcome his doubts. Together they agreed to meet again at this exact spot tomorrow at noon. After they separated, Katsuki swam back home to notify the other merfolk of his absence in advance. Hopefully Uraraka would be in an appeasing mood to take care of his rounds and was mentally preparing for the seashells he would have to collect as payment.

However, his plotting was interrupted by an eerie whistle, a high-pitched noise that bothered his webbed ears. A pod of dolphins blocked his way, and even worse, this was not out of their free will. For intelligent creatures, they knew better than to get involved with the merfolk and swam in their own business.

An ugly merman was among them, his face blackened and burnt by unknown horrors. The fin of his tail was dotted with holes and tattered at the edges, giving him the look of disease and infection. His hollow, sunken eyes were lifeless, as if he saw shit unimaginable to man; he was right, for the pain he experienced was a pain only his people faced.

"Dabi," Katsuki growled with his haunches raised.

His fingers twitched for his gift, but he was all out of juice. This was going to be a tough battle.

"Get out of my territory."

The rouge merman simply smirked. It was a smile reserved only for victory.

"Your territory?" he tried to be coy.

He outspread his arms with an army of other sea creatures in his wake.

"I live to disagree," he said as his smile grew wider.

* * *

Katsuki fought with tooth and nail until reinforcements arrived with ammo and willpower that even Dabi couldn't resist. A bite to his side. A burn mark to his chest. Those injuries were nothing to the blow he received as they reached the last stretch.

Before Katsuki toppled Dabi completely with the mermaids rooting for him to finish the job, a whirlpool of black wisps engulfed him, immediately transporting him to unknown waters and unknown places. The temperature of the water was too warm. The coral and sea life here had a different vibe. Even though he was not placed into the artic, he felt ice in his blood.

He frantically swam as much as he could, relentlessly pushing himself to the limit until he collapsed onto the ocean bed and crawled his way back home.

Izuku, Izuku, Izuku, his mind would repeat like a mantra. Izuku, Izuku, Izuku, his heart hammered along with the rhythm of his song. His fears became reality once he found Uraraka.

He embraced her, afraid he lost the rest of them in his absence, but they were strong. Their territory was safe, and Dabi would wreak havoc no more.

"Don't worry, Katsuki," she held his weary body and twirled him around. "We won! We overpowered Dabi and captured his elusive friend."

She puffed out her chest. "They won't bother us anymore."

Yet, their victory was not his priority, and that became clear to Uraraka as Katsuki shook and grasped her shoulders so tight, she winced from the claws digging into her skin. Yes, he was happy his friends were safe, but at what cost? What price?

"How many days?"

"Huh?"

"How many days have I been gone?!" he screamed, his heart shattering with each second.

There was a crazed look in his eyes, as if he had gone mad from the excursion. He was mad indeed, for only a man madly in love would feel the same sinking feeling in his chest.

"For two days…" Uraraka said, confirming his fears, which meant that Izuku was gone.

Katsuki felt the onset of dizziness, his breathing quickened until he couldn't tell the difference between the living and the dead. Before he knew it, he blacked out from both the exhaustion and heartbreak.

* * *

Izuku, he calls him. He calls him for hours stacked upon hours because Katsuki promised. He promised to be that anchor for him as he made his wish, but when the sun dipped low into the horizon and marked the end of the day, Izuku had to go. Loneliness was a feeling Izuku does not miss, but he continued on without looking back. His anxiety rose, for he was scared for Katsuki's well-being. The urge to make an excuse and plunge himself into the ocean to search for his love was strong, but Katsuki would never forgive him if he abandoned his son.

He doesn't know if he has the heart to forgive himself either, abandoning Izumi again, so he went with his gut and swam to a path he was all too familiar with. As if the sea witch had foreseen this visit, he waited for him at the entrance with a foreboding expression.

"What is your wish?" Aizawa asked him, cutting right to the chase.

The need for formalities was gone. There was only Izuku's wish and the sea witch who would grant it.

"My son," Izuku answered and bowed low, the lowest a seal of his size could prostrate before a powerful sea witch.

His tail brushed against the grainy sand, and Izuku thought of Katsuki's mark etched into his fur, into his skin, pushing him to be braver, stronger. He was ready, he told himself. He was ready to lose his arms if he must.

"Please," he begged. "Please let me save him. He doesn't know anything," Izuku pleaded with fear gripping his heart, envisioning his poor, sickly young boy grasping for the straws of life.

Without the ocean, he would experience a pain far greater than starvation and thirst, weakening him into a whisper. His hunger for the ocean would follow him into the afterlife, even if he was forever separated from his rightful home. His soul would continue to wander with unrest, the yearning in his heart never ceasing. He would be left in an excruciating, tortuous limbo, and no selkie, no matter how crude and vile they were, deserved such a cruel fate.

Aizawa watched Izuku with overwhelming sadness and regretted his next words.

"I can grant you that wish, but…"

The sea witch clenched his fists. His tentacles were taut with guilt. The consequences were pried through gritted teeth.

"In order to hold onto something dear to you…"

Aizawa turned away, unable to see Izuku's heartbreak, for he knew what came next, for he experienced a pain much similar to this. The ocean made its demand, and Aizawa wondered why so many of their kind continue to return to such an awful, fickle being.

"In order to hold onto your son," Aizawa said past the lump in his throat, "You have to let the other one go."

Izuku stilled.

 _To let the other one go._

"No," Izuku said, eyes hardened with grief. "Anything but that."

Flashes of Katsuki's smile, brazen and sharp, flittered in his mind.

"No, no, please," the selkie choked out. He shucked off his coat like a shell and gripped Aizawa's shoulders tight.

Snippets of Katsuki's voice poured into his ears like honey, and Izuku sobbed in his human form, not caring if he looked pitiful and naked in front of the sea witch. He doesn't care if he drowned.

"Take my hands, take my legs, but please," Izuku's thoughts slammed into Aizawa, pounding against his mind with a viciousness that could rival a hurricane.

The sea witch sorrowfully peeled Izuku's hands away. "Your memories of him would be wiped away," he explained. "You'll live with your son in bliss."

However, the unsaid, "Without him," was louder than anything else.

Izuku hugged his coat tight, but even with the solace of his greatest treasure, it did nothing to comfort him. Katsuki would have embraced him, placed his head into his chest and allowed the vibrations of his diaphragm rock him to sleep as he sung a sailor's tune. He would have known what to do, or at least attempted to haggle the price. He would have kissed him fiercely, all teeth and tongue, to remind him of their pure and unadulterated love. He would have understood Izuku's decision to go through great lengths to save his son.

Izuku wished he could kiss him goodbye. He wished he could have introduced Izumi to the merman who captured his heart.

But most of all, he wished that Katsuki would never find him, to forget about him and their wonderful memories together, for the ocean was never kind, never merciful. If Katsuki ventured back to Aizawa to find him, Izuku was afraid of the price, for true love was nothing in the sea's eyes.


End file.
